Atomic Spectra: Flame Tests
Introduce various metal salts (e.g. NaCl, SrCl2, CuCl2) into an open flame to produce brilliant colors associated with exciting metal cations.
Three flasks containing equal amounts of acetic acid are fitted with balloons containing different amounts of NaHCO3; mix the reagents by lifting and shaking the balloons: the balloons will inflate with CO2 to a volume proportional to the number of moles produced, in accordance with Avogadro’s law.
Boiling water at Room Temperature
Show water boiling at room temperature in a beaker in an evacuated bell jar, then put your hand in the water after boiling to convince students of its low temperature. (Upon request, we can give you a clean beaker and tap water if you want to drink the boiled water).
Burning Magnesium Ribbon
Burn a piece of magnesium ribbon in air to produce MgO.
Pour liquid nitrogen over a balloon to show that a decrease in T is accompanied by a decrease in V.
Combustion Ethanol Vapor
Allow a small amount of ethanol to vaporize in a large carboy, pour out the excess liquid, and hold a lighted splint to the mouth of the container – the impressive reaction also demonstrates the flammability of organic vapors.
Combustion of Methane Bubbles
Use a candle on a dowel rod to ignite large soap bubbles filled with CH4 – this is very impressive! If a more intense demo is needed, try Methane Bubbles XTREME.
Sugar and Salt – Use two conductivity testers with light bulbs to contrast the conductivity of d-H2O, sugar solution, and NaCl (aq), and tap water.
Strong and Weak Acids and Bases – Contrast the extent of ionization in weak and strong acids and bases using the lightbulb conductivity apparatus.
Dancing Green Goblin
Burning the methyl ester of boric acid produces a pure green flame that seems to “dance.”
Demonstrate the decomposition of 30% H2O2 in the presence of dishwashing liquid and KI, producing an upsurge of steaming foam.
React CaC2 and water to produce acetylene, then light the gas produced to force the pieces out of a pre-carved Jack-o-lantern. Halloween only.
Show the brilliant colors of metal cations in a fun way by igniting hydrogen balloons containing metal salts.
He and SF6 Balloons
Have adults inhale He or SF6 from balloons and then talk. HI-larious
Ignite a balloon filled with a stoichiometric mixture of hydrogen and oxygen to show the extremely exothermic reaction to produce water.
Pour solutions of luminol and H2O2 into a tall glass spiral to produce a beautiful chemiluminescent reaction. The light-emitting species is the dicarboxylate ion, aminophthalate, the product of the oxidation of luminol with H2O2.
Demonstrate the effect a decrease in P has on V by placing a marshmallow snowman in a bell jar and then evacuate the jar.
Methane Bubbles XTREME
Ignite a tower of methane-filled soap bubbles to produce a pillar of flame 3-5m high. As seen on Mythbusters!
Money to Burn
Soak a dollar bill in a water-alcohol mixture and then light it with a match; the high specific heat of water keeps the combustion temperature low enough to prevent burning the bill.
Potassium and Water
Drop a piece of potassium into a few inches of water and phenolphthalein in an aquarium to produce H2 (g) and KOH (aq) – the heat of reaction ignites the H2 (g) and a lavender flame is observed, and the indicator turns pink from the formation of KOH.
Allow a few students to experience what 1 atm (14.7 psi) “feels” like by resting an iron bar one inch square and 54 inches long on their toes.
Add a colorless liquid to 6 “empty” beakers, producing the colors of the rainbow – use this demonstration to show how evaluation of observations and experimental results leads to hypotheses and further testing (the scientific method).
Smashing Things with Liquid Nitrogen
Demonstrate the coolant properties of liquid nitrogen by freezing a racquet ball or another object of your choice and smashing it.
Yamada and Dry Ice
Add a chunk of dry ice to a 2 L cylinder containing a basic solution and Yamada universal indicator; the dry ice gradually acidifies the solution causing the color to change in the order purple, blue, green, yellow, orange.